Fuel supply pump for internal combustion engines



April 14, 1942. v Ron- N 2,279,403

- FUEL SUPPLY PUMP FOR INTERNAL COMBUSTION ENGINES Filed Oct. 5, 1939 Patented Apr. 14, 1942 FUEL sUPrLvruM'P FOR INTERNAL COMBUSTION mamas August Kottmann, Stuttgart, Germany; assignor to RobertBoschfiescllschaft mit beschritnkter Haftung, Stuttgart, Germany Application October 3,1939, Serial No. 297,758

' Germany October 22,1938

v2 Claims. (cuts-20s) v The present invention relates to a fuel supply pump for internal combustion engines and of the type having at least one inlet valve and an auxiliary hand pump arrangement. The present invention differs from known arrangements of this type, in that the cylinder of the hand pump device is screwed-directly into the housing of the fuel supply pump in place of the screw cap of the inlet valve. By this means it is a simple matter to convert fuel pumps into pumps having an auxiliary hand pumping device, by replacing the usual screw cap of the inlet valve by the cylinder of the hand pump. Moreover the device has the advantage that the housing of the fuel pump remains unchanged whether it be used as a pump with or without the hand pumping device. Thus the mounting of the pmnp is simplified.

The accompanying drawing shows. F18. 1, by way of example, a partiallongitudinal section through one form of construction of a fuel pump having a hand pumping .device. Fig.2 is an enlarged fragmentary sectional view showing the inlet valve and pump connectionon a larger scale. A fuel inlet connecting element l and a fuel outlet connecting element 3 are screwed into a housing I of a fuel delivery pump. The'housing I has a bore I withinwhich'is-disposed an inlet valve 4. An outlet valve (not shown) is alsoarranged within a bore of the housing, which hand pump I which is arranged co-axially with the valve. The element 0 has a bore I, which serves to guide a valve spindle 4a, and an annular space lll'housing a valve spring 9, which annular space is in communication with the cylindrical 1 space within the hand pump by bores or pas sages la. The pump I has a piston II with a piston rod l2, and a barrel is within the cylinder It. A handle I5 is attached to-the upper end of the piston rod' [2.

' For the purpose of rigidly holdingthe piston ll of the hand pump 1 in the position of rest, as shown in the drawing, the-upper end of the pistonrod is provided with a threaded part it, which, in the rest position, is brought into threaded engagement with a complementary thread I'I within the barrel I3. I

I declare that what I claim is: 1. In a mechanically operated fuel supply pump including a pump casing having a threaded opening and an inlet valve arranged in said opening, a hand-operated pump having a hollowpump including a pum'pcasing having a threadv ed opening, .and an inlet valve having a stem, and a valve spring arranged in said opening, a'

. hand-operated 'pump.. having. a hollow. threaded end screwed into said opening whereby said pump opens into the interior of said casing, said hollow end servingasa de for the inlet valve stem audas a casing f the inlet valvcspring.

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